This is one and a half potato chips per minute. from sun

At max Arizona Noon June insolation, 1000 W/m^2.

that is 1000 joules / sec / m^2

BTW I am supposedly 2.4 m^2 according to my Dr :-)
so half my body (eg, lying on the beach) is ca. 1 m^2.

1000 J = 1000 J / 4.12 J/cal = 250 cal = 0.25 Cal.  Per sec. (as watts are j/sec)


60/4 = 15 Cal per minute.  

This is one and a half potato chips per minute.